Annealing Electrical Steel

Annealing is a heat treatment process that alters the microstructure of a material causing changes in properties such as strength, hardness, ductility, and in some cases, chemical properties. For electrical steel laminations, the process of annealing is most commonly used to remove stresses in material around the edges of a lamination that are induced during punching. Another common application in the motor industry pertains to annealing special alloys such as cobalt or nickel to optimize electrical and mechanical properties for special designed high performance motors.

Continuous Annealing

Continuous Annealing is performed in a furnace line comprised of different zones. Each zone is dedicated to a certain cycle within the annealing process such as cleaning, heating, soaking, slow cooling, and fast cooling. Continuous Annealing furnaces are set up to run high production volumes for a particular grade material. The advantages of sourcing continuous annealing cycles for electrical steel laminations is typically a lower price per part cost, faster lead times, and the ability to run a high volume of parts. The disadvantage of continuous annealing cycles for laminations is a loss in flexibility to economically customize time, temperature, and atmosphere settings for a particular annealing cycle. Continuous annealing is most commonly used for M-Series Grain and Non-Grain Oriented materials as well as semi-processed electrical steels.

Batch Annealing

Batch Annealing is a process usually performed in an oven with one chamber. While there are many different styles of batch furnaces, the underlying advantage of this process is the flexibility and control over time, temperature, and atmosphere in the annealing cycle. The disadvantages of sourcing batch annealing are a higher cost per part, longer lead times, and a limitation to the number of laminations you can anneal in one cycle. Batch lamination annealing is most commonly used on special alloy laminations that contain cobalt or nickel, as well as applications with specific annealing instructions that need to be adhered to in which to achieve engineered desired results.